Sift-proof corner for use with flange packs



y 24, 1966 R. T. ELIAS 3,252,647

SIFT-PROOF CORNER FOR USE WITH FLANGE PACKS Filed NOV. 6, 1963 3 Sheets-Sheet 1 RoBERTTEuAs A ATTORNEYS May 24, 1966 R. T. ELIAS SIFT-PROOF CORNER FOR USE WITH FLANGE PACKS 3 Sheets-$heet 2 Filed Nov. 1965 O3 INVENTOR BERT T. Ems

to! lo? May 4, 1966 R. T. ELIAS 3,252,647

SIFT-PROOF CORNER FOR USE WITH FLANGE PACKS Filed Nov. 6, 1963 3 Sheets-Sheet 5 FIG."- K H INVENTOR ROBERT T. Ems

BY M I V F 421mm wwwfi M ATTORNEYS United States Patent Oflflce 3,252,647 Patented May 24, 1966 3,252,647 SIFT-PROOF CORNER FOR USE WITH FLANGE PACKS Robert T. Elias, Downers Grove, Ill., assignor to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed Nov. 6, 1963, Ser. No. 321,731 13 Claims. (Cl. 229-23) This invention relates to novel containers or cartons and more particularly to an improved corner construction and a method of producing sift-proof corners for such containers or cartons.

Previously known types of container or carton construction have included the desired result of providing a container or carton which has a flange on each of the three edges which lead up to a corner. The previously known types of construction produce corners which are structurally strong and are neat in appearance and which will present only a single thickness, or at most a double thickmess, of material to be adhered against the flanges of the front (or back) panel. The previously known methods produce corners which, even if they are made leak-proof by polyethylene, wax or other caulking, or patching agent, could be penetrated by a needle point without the needle point actually passing through any of the base material (usually paperboard) or between the layers of a lap seam. This is a characteristic of the vast majority of all corners which have ever been used in cartons, even including those commonly used for soap powder, etc., which have Van Buren Ear flaps as added precaution against sifting. Even certain cartons intended for liquids have this characteristic and depend for their leak-proof qualities upon the more or less uncertain chance of bridging the pin hole corner with wax or polyethylene, and once the bridge has been successfully made it still can be easily broken during handling of the container or carton.

It is an object of the present invention to provide containers or cartons which include a novel corner construction that eliminates the pin hole corner while at the same time includes a three-flange corner.

Another object of this invention is to provide a corner construction in which a liquid would, in every place, either have to go through the base material itself or else have to find its way between the layers of a lap seam, which seam could be made as broad as desired and which could be sealed with, as just two examples, either added adhesive, or polyethylene coating used as a heat seal.

Another object of this invention is to provide a corner construction which is tight enough to hold liquids and dusts and to prevent insect penetration and, in fact, is particularly useful in construction of polyethylene coated milk cartons.

Another object of this invention is to provide a corner construction for a carton comprising, a first panel and a second panel, a first flange forming panel disposed between and attaching the first and second panels to each other, and to provide a gusset and second and third flange forming panels which are attached to one of the first and second panels and to the gusset.

Another object of this invention is to provide a corner construction wherein the gusset is of rectangular or other polygonal shape and is foldable along a diagonal thereof, the orientation of which governs the angular relation between two of the adjacent ones of the three panels which cooperate to form the corner.

Another object of this invention is to provide a carton including vertical flanges and a sift-proof corner wherein the carton comprises a plurality of upstanding panels disposed in a tubular configuration and includes an end panel for closing the tubular configuration, the carton further including a plurality of flange forming panels and gussets attached to selected ones of the flange forming panels and cooperating with the other flange forming panels to provide a closed corner having flanges extending therefrom in three directions;

Another object of this invention is to provide a carton, of the type set forth above, wherein one of a pair of adjacent upstanding panels includes flange forming panels along horizontal edges thereof with gussets being disposed at each corner of the one upstanding panel.

Another object of this invention is to provide a carton wherein the gussets are attached to flange forming panels on the end panel rather than being attached to the upstanding panels.

A further object of this invention is to provide a method of constructing a corner wherein three adjacent panels are disposed in predetermined angular relation and are connected together by flanges each of which is in face-to-face engagement with one of a pair of connected panels and angularly related with the other of the pair of connected panels.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a plan view of a composite four-piece blank for constructing a carton in accordance with the present invention.

FIGURE 2 is an enlarged, fragmentary perspective view of a carton constructed from the blank illustrated in FIG- URE 1.

FIGURE 3 is a fragmentary perspective view, similar to the view which is illustrated in FIGURE 2, and shows the end panel in its closed position.

FIGURE 4 is an enlarged fragmentary perspective view of a selected corner of the carton shown in FIG- URE 2, and illustrates the position of a gusset and a horizontal flange prior to scaling of the end panel thereto.

FIGURE 5 is a vertical sectional view, taken on line 55 of FIGURE 3, and illustrates double thickness of the horizontal and vertical flanges and the quadruple thickness of the reinforced corner construction.

FIGURE 6 is a fragmentary perspective view of a modified form of carton in which the end panel is provided with a gusset at each corner thereof.

FIGURE 7 is a fragmentary perspective view of one corner of the end panel which is shown in FIGURE 6, and illustrates an intermediate position of the gussets during the folding thereof.

FIGURE 8 is a fragmentary perspective view, similar to FIGURE 7, and illustrates the gusset in its final folded form.

FIGURE 9 is a fragmentary perspective view of another modified form of carton, which form differs from the carton of FIGURE 2 in that the end panel is hingedly attached to a recessed one of the upstanding side panels.

FIGURE 10 is a fragmentary perspective view of still another modified form of carton, which form differs from the form of FIGURE 6 in that the end panel which includes the gussets is hingedly attached to a recessed one of the upstanding panels.

FIGURE 11 is a plan view of a fragmentary portion of a blankfor constructing a flanged corner in accordance with the present invention.

FIGURE 12 is a perspective view and illustrates the fragmentary portion of the blank, of FIGURE 11, in a partially folded condition.

FIGURE 13 is a fragmentary perspective view of a corner which is constructed from the fragmentary portion of the blank of FIGURE 11.

FIGURES 14, 15, 16, 17 and 18 are plan views of various fragmentary portions of blanks which are used to produce corner constructions in accordance with the present invention.

FIGURES 19, 20, 21 and 22 are sequential line drawings which illustrates the various steps in a method for designing corners having various angles between the planes in which the various panels thereof are disposed.

Referring to the drawings in detail, there is shown in FIGURE 1, a four-piece composite blank, generally indicated by the numeral 10, which blank includes a first pair of rectangular shaped upstanding panels 11 and a .second pair of rectangular shaped upstanding side panels 12. Each of the pair of panels 12 is provided along one edge thereof with a rectangular shaped end panel 13.

Each of the pair of upstanding panels 11 is provided with a pair of vertical flange forming panels 14 and a pair of horizontal flange forming panels 15. The flange forming panels 14 are attached to the panel 11 along parallel longitudinally extending fold lines 16, and the flange forming panels 15 are attached to the panel 11 along parallel transversely extending fold lines 17. The pairs of fold lines 16 and 17 intersect at each corner of the panel 11 to form rectangular gussets 18 at each of the four corners of the panel 11. Each of the gussets .18 is provided with a diagonal fold line 19 for a purpose to be later described. Each of the gussets 18 is divided by the diagonal fold line 19 into a pair of tri' angular portions 20 and 21.

Each of the panels 12 has one edge which is defined by a transverse fold line 22. The length of the panels 12 is equal to the length of the panels 11 plus the width of the pair of flange forming panels 15, as is clearly shown in FIGURE 1. Each of the panels 12 is provided along the longitudinally extending edge portions thereof with flange forming portions 23 which are preferably coated with glue or other suitable adhesives.

The end panels 13 are each provided with a pair of parallel fold lines 24 and 25 which define flange forming panels 26 and 27 respectively.

Illustrated in FIGURES 2 through 5 is a container or carton, generally indicated by the numeral 30, which is constructed from the composite blank 10. As viewed externally of the carton 30, the flange forming panels 14 are folded outwardly along the fold lines 16 and are secured to the panels 12 along the flange forming portions 23. Thus, the panels 11 are recessed inwardly from the edges of the panels 12 and the carton 30 is thereby provided with a plurality of vertical flanges 31, as is shown in FIGURES 2, 3 and 4. After the carton 30 is assembled into the form illustrated in FIGURE 2, the horizontal flange forming panels 15 are folded outwardly and downwardly along the fold lines 17 and the gussets 18 are folded along the diagonal fold line 19 such that the triangular portion 21 is brought into face-to-face engagement with the triangular portion 20, as clearly shown in FIGURE 4.

After the carton 30 has been erected to the tubular configuration which is illustrated in FIGURES 2 and 4, the end panel 13 is recessed between the upstanding panels 12 such that the flange forming panels 26 and 27 are brought into face-to-face engagement with the triangular portions 21, of the gussets 18, and edge portions of the end panel 13 are brought into engagement with the flange forming panels 15. The flange forming panels 27 are either heat-sealed or adhesively secured to the triangular portions 21 and to the panels 12, and the end panels 13 are heat-sealed or adhesively secured to the flange forming panels 15. Thus, the carton 30 is provided with a threeflange, leak-proof corner construction from which, to escape, a liquid would in every place either have to go through the base material itself or else have to find its way between the layers of a lap seam which could be as broad as desired.

Referring to FIGURES 6, 7 and 8, there is illustrated a modified form of container or carton, generally indicated by the numeral 40, which includes a pair of recessed upstanding panels 41, which correspond to the panels 11 as illustrated in FIGURES 1 through 5, and a pair of upstanding panels 42 which have attached at one end thereof an end panel 43. The end panels 43 (only one being illustrated) are attached to the upstanding side panel 42 along a horizontal fold line 44 and include longitudinally extending flange forming panels 45 and transversely extending flange forming panels 46. The end panel 43 is provided at each of the four corners thereof with a gusset, generally indicated by the numeral 47, each of which is divided by a diagonal fold line 48 into a pair of triangular portions 49 and 50.

Each of the upstanding recessed panels 41 is provided with a pair of longitudinally extending flange forming panels 51 which are heat-sealed or adhesively secured to the upstanding panels 42 to provide the tubular configuration which is illustrated in FIGURE 6. The flange forming panels 45 and 46, on the end panel 43, are folded upwardly along their respective fold lines and the gussets 47 are folded inwardly along the diagonal fold lines 48, as is illustrated in FIGURES 7 and 8. The end panel 43 is then recessed within the upstanding panels 41 and 42 and the flange forming panels 45 and 46 are heatsealed, or otherwise adhesively secured to marginal portions of the adjacent upstanding panels 42 and 41, respectively. In this form of the invention, it is preferable that the triangular portions 49 and are heat-sealed or otherwise adhesively secured together. Thus, there has been provided a container or carton 40 which includes a three-flange, leak-proof corner construction.

Another modified form of container or carton, generally indicated by the numeral 55, is illustrated in'FIG- URE 9. The carton 55 includes a pair of recessed upstanding panels 56 and 57, a second pair of upstanding panels 58 and 59 and a pair of end panels 60 (only one of which is illustrated). The end panel 60 is attached to the recessed upstanding panel 57 by a flange forming panel 61, and it is to be understood that an identical end panel is attached by a flange forming panel to the lower edge of the recessed upstanding panel 56. The end panel 60 includes a pair of flange forming panels 62 and 63 and, in this respect, is similar to the end panel 13 which is illustrated in FIGURES 1 through 5.

The recessed upstanding panel 56 includes a pair of vertically extending flange forming panels 64 and 65, a transversely extending flange forming panel 66 and a gusset 67 at each of the four corners thereof. The gussets 67 each include a diagonal fold line 68 which divides the gussets 67 into triangular portions 69 and 70.

After the carton 55 has been erected to the position which is illustrated in FIGURE 9, the various flange forming panels 61 and 66 are folded outwardly and downwardly along their respective fold lines and the gussets 67 are folded along the diagonal fold lines 68 to bring the triangular portion 69 and 70 into face-to-face engagement. The flange forming panels 62 and 63 on the end panel 60, are folded upwardly along their respective fold lines and the end panel 60 is then brought into recessed alignment with upper marginal portions of the upstanding panels 58 and 59. The end panel 60 is then heatsealed, or adhesively secured, to the horizontally disposed'flange forming panels 61 and 66, and the flange forming panels 62 and 63 are heat-sealed, or adhesively secured, to upper marginal portions of the upstanding panels 58 and 59. Thus, the completed carton 55 is provided with corner constructions having flanges extending therefrom in three directions. In addition, the corner construction is formed without the usual pinhole which was referred to above with respect to the prior art.

Illustrated in FIGURE 10 is another modified form of container or carton, generally indicated by the numeral 75, which is similar to the carton 55 of FIGURE 9 in that the carton has end panels 76 (only one being shown) which are attached to respective recessed upstanding panels 77 and 78. Each of the recessed panels 77 and 78 includes a pair of vertically disposed flange forming panels 79 and 80 which are heat-sealed, or adhesively secured, to respective ones of a pair of upstanding panels 81 and 82.

The end panel 76 is similar to the end panel 43, as is illustrated in FIGURE 6, in that the end panel 76 includes a pair of transversely extending flange forming panels 83 and 84, and a pair of longitudinally extending flange forming panels 85 and 86. Further, the end panel 76 is provided at each of the four corners thereof with a rectangular gusset, generally indicated by the numeral 87, each of which includes a diagonal fold line 88 that divides the gusset 87 into a pair of triangular portions 89 and 90.

After the carton 75 has been erected to the tubular configuration which is illustrated in FIGURE 10, the flange forming panels 83, 84, 85 and 86, are folded upwardly along their respective fold lines and the gussets 87 are folded along the diagonal fold lines 88 to bring the triangular portions 89 and 90 into face-to-face engagement in the same manner as is illustrated in FIGURES 7 and 8.

After sealing the triangular portions 89 and 90 together, the end panel 76 is recessed within upper marginal portions of the upstanding panels 77, 78, 81 and 82. The flange forming panels 85 and 86 are heat-sealed, or adhesively secured to the upstanding panels 81 and 82, and the flange forming panels 83 and 84 are heat-sealed, or adhesively secured, to the recessed upstanding panels 77 and 78. Thus, the carton 75 is completed and includes corner constructions with flanges extending outwardly therefrom in three directions. Further, the corner construction is leak-proof and does not include the previously referred to pinhole as in the prior art.

FIGURES ll, 12 and 13 illustrate a one-piece blank, generally indicated by the numeral and the manner in which the blank 100 is folded to form a corner construction, generally indicated by the numeral 101, which has flanges extending outwardly therefrom in three directions. The blank 100 includes a plurality of fold lines which define a first panel 102, a second panel 103, three flange forming panels 104, and 106, and a gusset which includes a pair of triangular portions 107 and 108. After the blank 100 has been folded, the corner construction 101 is completed by securing a third panel 109, which is either heat-sealed, or adhesively secured, to the triangular portion 108 and to the flange forming panels 105 and 106.

In folding the blank 100 to form the corner construction 101, the exact sequence of folding is immaterial and it is only the final arrangement which is significant. The

blank 100 is folded so that, as observed from the outside of the corner construction 101, lines AB, CD, CF and GC become troughs and the lines GE and BC become ridges. The points B and H are brought together, thus, the line GH] is kept as one straight line. It will be noticed that the side exposed to the contents of the container or carton (in the case of a usual polyethylene coated milk carton, the inside has a heavier coating to prevent pinholes in the coating) will be the only side which is presented for adherence against the third panel 109. It will also be noted, that in the gusset (the back side of GBC against the back side of KABG) the same more heavily coated side will be against itself. That is, if adhesive were used, it could all be applied to the same side of the paperboard or other carton material. If a heat-seal coating were used, it need be on only one side as far as adhesive needs would go. If a paper were used with heat-seal coating on both sides, and if the inside had the heavier coating, the seal would involve the lighter coating between areas GBC and HGC, but the more important other seals (against the third panel and in the KABG gusset area) would have the advantage of bringing together two layers of the heavier coating. That is, two layers of the lighter coating might not give perfect adhesion; a layer of the lighter against a layer of the heavier coating would be better; but two layers of the heavier coating would give the best and strongest seal.

The corner construction 101, just described, produces flange 104 coplanar with the first panel 102. By exactly the same principle, applied as its mirror image, the flange 104 could have been made coplanar with the second panel 103. In this case, instead of a trough from G to C, there would be a trough from B to H, while BE would become a trough and HF a ridge, and the main folding step would be to bring points G and C together. It is not required that all flanges at a corner, or even two of them, should be the same height. The relative widths of the flanges may be changed, without upsetting the basic principle, merely by trimming down or adding onto one or both of the coplanar flanges, or by trimming one flange and adding to the other flange.

Referring to FIGURE 13, it will be noted that each of the panels 102, 103 and 109 is disposed normal to each of the other two panels. This right-angle corner construction results from the angles ABE and FCD each being equal to 90, and the gusset GBCH being square such that the angle BCG is 45. The basic principle which is involved in forming corner constructions, of

-the type described above, is not limited to right-angle corner constructions. Thus, by varying any of the angles ABE, FCD or BCG, various types of corners may be constructed.

In FIGURE 14 there is illustrated a fragmentary portion of a blank, generally indicated by the numeral 110. The blank 110 includes a first panel 111, a second panel 112, a pair of gusset forming triangular portions 113 and 114, and three flange forming panels 115, 116 and 117. The triangular portions 113 and 114 are elongated along the lines GB and HC, respectively, so as to form an oblong rectangular gusset, generally indicated by the nu meral 118. As is illustrated in FIGURE 14, the angles ABE and FCD are each 'equal to 90 while the angle BCG is greater than 45. After folding the blank 110 in the same manner as previously described with regard to the blank 100, and after providing a third panel (not shown) such as the panel 109 in FIGURE 13, a corner construction will be formed wherein the first panel 111 and the second panel 112 meet at an obtuse angle. 'In this case, however, points B and H would not be superimposed; B would move toward H and come to rest in the GHC plane but would not touch H. In this form, the panels 111 and 112 would not be perpendicular to each other, but each would be perpendicular to the third panel (not shown).

Illustrated in FIGURE 15 is another modified portion of a blank, generally indicated by the numeral 120, for forming another type of corner construction. The blank 120 includes a first panel 121 and a second panel 122, which panels include right-angles ABE and FCD, respectively. A rectangular gusset forming portion, generally indicated by the numeral 123, is elongated along the lines BC and GH such that the angle BCG is less than 45. After folding the blank 120 in the same manner as previously described, a corner construction would be produced in which the first panel 121 and the second panel 122 would meet at an acute angle. Point B, in moving toward H, would rest in the plane of GHC but outside the line GH. The panels 121 and 122, while not perpendicular to each other, would each be disposed normal to the third panel, not shown.

It is also possible with the same basic principle to form corners in which no panel is perpendicular to any other. As is illustrated in FIGURE 16, another modified form of blank, generally indicated by the numeral 130, includes a first pane-l 13-1, a second panel 13-2 and a gusset 7 forming panel generally indicated by the numeral 133. The blank 130 includes an angle ABE which is greater than'90, an angle FCD which is less than 90 and an angle BCG which is greater than Consequently, the blank 130 will yield a corner in which the first panel slants inward toward the contents while the second panel slants outward and neither the first panel 131 nor the second panel 132 is perpendicular to the third panel (not shown).

A modified form of blank, generally indicated by the numeral 140, is illustrated in FIGURE 17 and includes a first panel 141, a second panel 142 and an irregular shaped gusset forming panel .143. The angles ABE and FCD are each less than 90 and the angle BGC is less than 45 Folding the blank 140, in the manner previously described, will produce a corner in which each of the first, second and third panel-s intersects with each of the other two panels at an acute angle, so that both the [first panel and a second panel slants inwardly,

On the other hand, the modified form of blank, generally indicated by the numeral 150 in FIGURE 18, will produce a corner in which each panel of a first panel 151, "a second panel 152, and a third panel (not shown) intersects with each of the other two panels at an obtuse angle so that the first panel and the second panel slant outwardly.

The blank 150 forms such a corner construction because the angles ABE and FCD are greater than 90 and the angle BCG is larger than 45 type of corner construction would lend itself to the construction of containers in the class of trays, bowls and dishes, such containers differing from cartons in that, in the terminology used' above, there would be rear panels, side panels, everything but a front panel. Construction of this kind could be thought of as providing a buttress at each corner, and it should be remembered that the corners may be made leak-proof.

Throughout this discussion, the term containers should be taken to include also covers or lids of the telescoping type. v p

A general rule may be stated for designing corners having various angles between the planes in which the various panels are disposed. Such a general rule is illustrated by the line drawings in FIGURES 19 through 22.

It is to be understood that a first panel (not shown), but similar to the panel 109 which is shown in FIGURE 13) may be provided and heat-sealed, or adhesively secured, to the corner construction hereinafter described.

As is shown in FIGURE 19, a first construction line 16 1 and a second construction line 162 are formed such that they intersect to form a first included angle ABE, which angle is equal to a desired predetermined angle between the first panel (not shown) and a second of the panels to be later described. A third construction line 163 is formed parallel to the first construction line 161 and is spaced therefrom a distance equal to the desired width of a flange 164 which connects the second panel to the third panel.

As is shown in FIGURE 20, a fourth construction line 165 is drawn from the intersection of the first construction line 161 and the second construction line 162 (at the point B) such that the fourth construction line 165 and the first construction line 161 form the included angle EBC which is equal to the previously formed angle ABE. A fifth construction line 166 is formed so as to extend from the intersection of the third construction line 163 and the fourth construction line 16 5 from the point C to the point D. The fifth construction line 166 is disposed so that a second included angle FCD, between the third construction line 163 and the fifth construction line 166, is equal to a desired angle between the first and third panels.

This particular As is set forth above, .the first panel (not shown) is similar to the panel 109 which is shown in FIGURE 13. The second panel is generally indicated by the numeral 167, as in FIGURE 20, and includes the angle FCD. The third panel is generally indicated by the numeral 168, in FIGURE 20, and includes the angle ABE.

As is shown in FIGURE 21, a sixth construction line f 169 has been formed and extends outwardly from the intersection of the third, fourth and fifth construction lines (at the point C) and forms the included angle BCG. This included angle BCG, between the fourth construction line and the sixth construction line 169, is equal to the desire-d predetermined angle between the second panel 167 and the third panel 168 plus the included angle between the fifth construction line 166 and the sixth construction line 169 minus 180. In other words, the apex angle of the first panel (not shown) equals 180, plus the angle GCB, minus the angle GOD.

As is shown in FIGURE 22, a seventh construction line 170 is formed parallel to the second construction line 162 and is spaced outwardly from the third panel 168 a distance equal to the preferred width of a flange 171 which connects the third panel [168 to the firstpanel (not shown). An eighth construction line 172 is formed parallel to the fifth construction line 166 and is spaced outwardly from the second panel 167 a distance equal to the preferred width of .a flange .173 which connects the second panel 167 to the first panel (not shown).

It will be noticed that in FIGURE 22 the flanges 171 and 176 were cut, as a matter of preference in such a way that point G was removed, whereas in the previous figures, point G was allowed to remain as determining the edges of the flanges. The seventh construction line 17 0 does not have to intersect with the line GC but may merely extend between the points K and P. Likewise, the eighth construction line 172 only needs to intersect with the line GC, as at point Q, and the material may be notched along the line PBQ.

The blank 100, as is shown in FIGURE 11, is used to form the corner construction 101 which is shown in FIGURE 11. The corner construction 101 is of the type wherein the three panels are arranged with each panel being perpendicular to the other two panels. Further, the flanges 104, 105 and 106 are all of the same width. In this type of construction, the point G falls at the edge of the flange 105 and the points KGHJ are in an uninterrupted straight line. This means that the panels 102 and 103 may be one simple rectangular strip without need of notching or cutting and without waste, The fact that the corner constructions may be made of simple rectangular or ribbon like shapes without cutting or waste is considered to be a major advantage of this invention.

The above described corner constructions, containers or cartons may be constructed of paperboard, heavy paper, plastic or other similar flexible materials.

While preferred forms and arrangement of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made, and variations of the preferred method steps may be made, without departing from the spirit and scope of the invention as defined in the appended claimed subject matter.

I claim: 7

1'. A corner construction for a carton comprising, a first panel, a second panel and a third panel, a first flange forming panel disposed between and attaching said first and second panels to each other, a gusset, said gusset being attached to said first flange forming panel; and second and third flange forming panels each attached to one of said first and second panels and to said gusset, said gusset being of rectangular shape and being foldable along a diagonal thereof, wherein said rectangular shape is a square, said first and second panels being disposed at right angles to each other and to said second and third flange forming panels.

2. A corner construction for a carton comprising, a first panel, a second panel and a third panel, a first flange forming panel disposed between and attaching said first and second panels to each other, a gusset, said gusset being attached to said first flange forming panel; and second and third flange forming panels each attached to one of said first and second panels and to said gusset, said gusset being of rectangular shape and being folda-ble along a diagonal thereof wherein said rectangular shape is elongated along the sides thereof which are attached to said second and third flange forming panels, and said first and second panels meet at an obtuse angle.

3. A corner construction for a carton comprising, a first panel, a second panel and a third panel, a first flange forming panel disposed between and attaching said first and second panels to each other, a gusset, said gusset being attached to said first flange forming panel; and

second and third flange forming panels each attached to one of said first and second panels and to said gusset, said gusset being of rectangular shape and being foldable along a diagonal thereof wherein said rectangular shape is elongated along the side thereof which is attached to said first flange forming panel, and said first and second panels meet at an acute angle.

4. A corner construction for a carton comprising, a first panel, a second panel and a third panel, a first flange forming panel disposed between and attaching said first and second panels to each other, a gusset, said gusset being attached to said first flange forming panel; and second and third flange forming panels each attached to one of said first and second panels and to said gusset, wherein said gusset has a short side connected to one of said second and third flange forming panels, and a long side connected to the other of said second and third flange forming panels; said first flange forming panel intersecting with at least one of said second and third flange forming panels at an obtuse angle to form a corner in which no panel is perpendicular to another panel.

5. A corner construction for a carton comprising, a first panel, a second panel and a third panel, a first flange forming panel disposed between and attaching said first and second panels to each other, a gusset, said gusset being attached to said first flange forming panel; and second and third flange forming panels each attached to one of said first and second panels and tosaid gusset, wherein said first panel includes an acute angle which is defined by the intersection of said first flange forming panel with one of said second and third flange forming panels, and said second panel includes an acute angle which is defined by the intersection of said first flange forming panel with the other of said second and third flange forming panels, whereby the first and second panels slant inward.

6. A corner construction for a carton comprising, a first panel, a second panel and a third panel, a first flange forming panel disposed between and attaching said first and second panels to each other, a gusset, said gusset being attached to said first flange forming panel; and second and third flange forming panels each attached to one of said first and second panels and to said gusset,

Val

wherein said first panel includes an obtuse angle which is defined by the intersection of said first flange forming panel with one of said second and third flange forming panels, and said second panel includes an obtuse angle which is defined by the intersection of said first flange forming panel with the other of said second and third flange forming panels, whereby the first and second panels slant outward.

7. A carton including vertical flanges and a sift-proof corner, said carton comprising a plurality of upstanding panels disposed in a tubular configuration and a single planar end panel for closing said tubular configuration, said end panel and a pair of adjacent ones of said upstanding panels cooperating to form said sift-proof corner, said adjacent panels including flange forming panels for providing said carton with upstanding flanges, said end panel including flange forming panels for providing said carton with horizontally extending flanges, said horizontally extending flanges being planar and each being disposed in a vertical plane, and gusset means on one of said flange forming panels and cooperating with the other flange forming panels to provide a closed corner having flanges extending therefrom in three directions.

8. A carton as defined in claim 7 wherein one of said pair of adjacent upstanding panels includes flange forming panels along horizontal edges thereof, said gusset means being disposed at each corner of said one upstanding pnael.

9. A carton as defined in claim 8 wherein said end panel is attached to the other of said pair of adjacent upstanding panels.

10. A carton as defined in claim 8 wherein said end panel is attached to said one of said pair of adjacent upstanding panels.

11. A carton as defined in claim 7 wherein said end panel includes flange forming panels along each edge thereof, and said gusset means are disposed at each corher of said end panel.

12. A carton as defined in claim 11 wherein one of said adjacent upstanding panels is recessed inwardly from an edge of the other of said adjacent upstanding panels, and said end panel is attached along a fold line to said other of said adjacent upstanding panels.

13. A carton as defined in claim 11 wherein one of said adjacent upstanding panels is recessed inwardly from an edge of the other of said adjacent upstanding panels, and said end panel is attached along a fold line to said one of said adjacent uptsanding panels.

References Cited by the Examiner UNITED STATES PATENTS 1,065,398 6/1913 Scudder 22943 1,147,650 7/1915 Scudder 229--37 1,173,752 2/ 1916 Smith 22943 1,703,399 2/1929 Lange 229-23 2,737,336 3/1956 Moore 22943 3,063,593 11/ 1962 Kuchenbecker 229-23 JOSEPH R. LECLAIR, Primary Examiner. FRANKLIN T. GARRETT, Examiner. J. F. MCNULTY, Assistant Examiner, 

1. A CORNER CONSTRUCTION FOR A CARTON COMPRISING, A FIRST PANEL, A SECOND PANEL AND A THIRD PANEL, A FIRST FLANGE FORMING PANEL DISPOSED BETWEEM AND ATTACHING SAID FIRST AND SECOND PANELS TO EACH OTHER, A GUSSET, SAID GUSSET BEING ATTACHED TO SAID FIRST FLANGE FORMING PANEL; AND SECOND AND THIRD FLANGE FORMING PANELS EACH ATTACHED TO ONE OF SAID FIRST AND SECOND PANELS AND TO SAID GUSSET, SAID GUSSET BEING OF RECTANGULAR SHAPE AND BEING FOLDABLE 